SS7 is a signaling protocol used internationally to establish and tear down calls and to query databases for information relating to calls and subscribers. However, different countries use different variations of the SS7 protocol. For example, in the United States, ANSI SS7 is the dominant signaling protocol. In Europe, individual countries use ITU-N SS7 for signaling in networks within the countries. For signaling between countries, the ITU-I SS7 protocol is used. Each of these SS7 protocol variations include different message formats. Within national networks, signaling nodes, such as signal transfer points and service control points, are typically configured to recognize only one SS7 protocol variation. Gateway nodes are placed between networks to convert from one SS7 protocol variation to another protocol variation. However, these gateway nodes are simply protocol converters. These protocol converters do not have the capability to intelligently redirect or process messages based on SS7 protocol variation.
In some instances, it may be desirable to redirect messages to a service control point of a particular SS7 protocol variation. For example, as illustrated in FIG. 1, an ANSI STP 100 is connected to an ANSI SCP 102 and an ANSI SS7 network 104. In one processing scenario, it may be desirable to allow calls from ANSI SS7 network 104 to be completed only during certain times of day. The times of day that calls are allowed may be stored in ANSI SCP 102. Accordingly, when ANSI SS7 network 104 sends an ANSI ISUP message to a destination end office, ANSI STP 100 may redirect the ISUP message to ANSI SCP 102 to determine whether the call should be allowed. This redirection may be accomplished by encapsulating the ANSI ISUP message in an SCCP unit data message, which is in turn encapsulated in an MTP message. ANSI SCP 102 receives the encapsulated message, determines whether the call should be completed, and if the call is allowed, forwards the ISUP message to its intended destination.
Conventional STP redirect functions are capable of redirecting messages formatted according to a single SS7 protocol variation. Thus, when ANSI STP 100 illustrated in FIG. 1 receives an ITU-N message or ITU-I ISUP message, the message would be discarded. Discarding messages relating to a call is undesirable, since the calls would not be completed. Accordingly, there exists a need for improved methods and systems for identifying, redirecting, and processing messages of different SS7 protocol variations.